It's a case of what the market will pay
@TartanPaint, if you really want one and are looking for one then that might push it up, but they really are a one trick pony for me. I only use when I'm working with jersey so a lot of the time they are in a bag.
I have sold one in 2016 and I think it was for £200, the one I bought after it, the next model was £360 (with some dealing with Russell at SMD,cash off to knock the 'extras' off. Having had both I consider the 2000CPX the better machine (it would be wouldn't it). I never seen to do as much twiddling, sometimes even just moving on from one lot of jersey to the next without any changes. If I had cash coming out my ears I would buy a Babylock, but for something that normally sits in a bag 80% of sewing time, I'll stick.
The Bernina 1150MDA, the overlocker I have, bought around 2013 was a demo machine at £485. Now that does earn its keep and although that's an old model now I wouldn't upgrade unless it died.